1. Technical Field
The present invention relates to a method for preparing a multilayer metal complex having excellent surface properties. More particularly, the present invention relates to a method for preparing a multilayer metal complex having a low cost metal-core/noble metal-shell structure, which has a high mass fraction of noble metals, and exhibits excellent surface properties and dispersity.
2. Description of the Related Art
Metal complexes having a low cost metal-core/noble metal-shell structure capable of being used as low cost conductive pastes and electromagnetic shielding substances are known in the art and exhibit excellent conductivity to provide high reliability when applied to products.
For metal complexes used in such purposes, it is important that noble metals forming a shell structure are uniformly and sufficiently adhered to a surface of a low cost metal, thereby secure a sufficient thickness.
Complexes of a copper core/silver shell structure are widely used in the art. Conventionally, a copper-silver complex is prepared by a liquid phase reduction method. All processes of the liquid phase reduction method are carried out in liquid phase. However, this method has problems in that aggregation can easily occur due to interfacial effects between a solid phase and a liquid phase and an excess of reducing agents, and separation of silver particles also occurs, thereby making it difficult to obtain a complex with a uniform surface. In addition, when a large amount of silver ions is introduced in order to increase silver content, the silver ions are uniformly dispersed on the surface of copper, making it difficult to obtain a thin silver layer, and voids are generated inside the complex due to active melting of copper.
Therefore, there is a need for a method for preparing a novel metal complex through controlled process conditions so as to solve the above problems and provide excellent surface properties.